Nested lists in Python - Mini Project: Build & Apply

Working with Nested Lists in Python

📖 Scenario: You are organizing a small library's book shelves. Each shelf holds a list of book titles. The library has three shelves.

🎯 Goal: You will create a nested list representing the shelves and their books, then count how many books are on each shelf, and finally print the counts.

📋 What You'll Learn

Create a nested list called library_shelves with exactly three inner lists, each containing the exact book titles specified.

Create a list called book_counts to store the number of books on each shelf.

Use a for loop with the variable shelf to iterate over library_shelves.

Append the length of each shelf to book_counts.

Print the book_counts list.

💡 Why This Matters

🌍 Real World

Nested lists help organize grouped data like shelves of books, classrooms of students, or menus with categories.

💼 Career

Understanding nested lists is important for data organization, processing multi-level data, and working with complex datasets in many programming jobs.

1

Create the nested list of shelves

Create a nested list called library_shelves with three inner lists. The first list should have 'The Hobbit' and '1984'. The second list should have 'Pride and Prejudice', 'To Kill a Mockingbird', and 'The Great Gatsby'. The third list should have 'Moby Dick'.

Python

# Create the nested list library_shelves with the exact books
# Your code here

Need a hint?

Remember, a nested list is a list inside another list. Use square brackets [] for each shelf.

2

Create the list to hold book counts

Create an empty list called book_counts to store the number of books on each shelf.

Python

library_shelves = [
    ['The Hobbit', '1984'],
    ['Pride and Prejudice', 'To Kill a Mockingbird', 'The Great Gatsby'],
    ['Moby Dick']
]

# Create an empty list called book_counts
# Your code here

Need a hint?

Use [] to create an empty list named book_counts.

3

Count books on each shelf

Use a for loop with the variable shelf to iterate over library_shelves. Inside the loop, append the number of books on the current shelf to the book_counts list using len(shelf).

Python

library_shelves = [
    ['The Hobbit', '1984'],
    ['Pride and Prejudice', 'To Kill a Mockingbird', 'The Great Gatsby'],
    ['Moby Dick']
]

book_counts = []

# Use a for loop with variable shelf to iterate over library_shelves
# Append the length of shelf to book_counts
# Your code here

Need a hint?

Use for shelf in library_shelves: to loop. Use len(shelf) to get the number of books.

4

Print the book counts

Write a print statement to display the book_counts list.

Python

library_shelves = [
    ['The Hobbit', '1984'],
    ['Pride and Prejudice', 'To Kill a Mockingbird', 'The Great Gatsby'],
    ['Moby Dick']
]

book_counts = []

for shelf in library_shelves:
    book_counts.append(len(shelf))

# Print the book_counts list
# Your code here

Need a hint?

Use print(book_counts) to show the list of counts.